Alright, let's work through 3829 times 5521 step by step
3829 × 5521 = 5521 × (3829)
+ 5521 × 9 that is equal 49689
+ 5521 × 20 what gives us 110420
+ 5521 × 800 that is equal 4416800
+ 5521 × 3000 that results in 16563000

= 21139909
